%0 journal article
%@ 0939-6411
%A Mathew, S.,Baudis, S.,Neffe, A.T.,Behl, M.,Wischke, C.,Lendlein, A.

%D 2015
%J European Journal of Pharmaceutics and Biopharmaceutics  A
%N 
%P 18-26 
%R doi:10.1016/j.ejpb.2015.03.025
%T Effect of diisocyanate linkers on the degradation characteristics of copolyester urethanes as potential drug carrier matrices
%U https://doi.org/10.1016/j.ejpb.2015.03.025
 
%X In this study, the effect of three aliphatic diisocyanate linkers, L-lysine diisocyanate ethyl ester (LDI), hexamethylene diisocyanate (HDI), and racemic 2,2,4-/2,4,4-trimethyl hexamethylene diisocyanate (TMDI), on the degradation of oligo[(rac-lactide)-co-glycolide] (64:36 mol%) based polyester urethanes (PEU) was examined. Samples were characterized for their molecular weight, mass loss, water uptake, sequence structure, and thermal and mechanical properties. Compared to non-segmented PLGA, the PEU showed higher water uptake and generally degraded faster. Interestingly, the rate of degradation was not directly correlating with the hydrophilicity of the diisocyanate moieties; instead, competing intra-/intermolecular hydrogen bonds in between urethane moieties appear to substantially decrease the rate of degradation for LDI-derived PEU. By comparing microparticles (μm) and films (mm) as matrices of different dimensions, it was shown that autocatalysis remains a contributor to degradation of the larger-sized PEU matrices as it is typical for non-segmented lactide/glycolide copolymers. The shown capacity of lactide/glycolide-based multiblock copolymers to degrade faster than PLGA and exhibit improved elastic properties could be of interest for medical implants and drug release systems.